This invention relates to ratchet wrenches having shanks holding socket heads to install and tighten nuts onto machine bolts and to break loose and remove nuts from machine bolts, for example.
Particularly, the invention relates to a ratchet wrench which can be used in a first configuration to cause force on the wrench handle to be applied directly to the shank to tighten or loosen nuts associated with a socket head on the shank; and can be used in a second configuration wherein the handle can be moved to cause the shank to rotate rapidly to spin the nut on or off of a bolt.
It is known to provide wrenches which can operate in one configuration to apply direct torque to a shank and in another configuration to rapidly rotate the shank under conditions of lesser load. For example, see U.S. Pat. No. 1,429,386 to Watson, issued in September of 1922, which provides a wrench structure by which nuts may be quickly run up or down on a bolt and then loosened or tightly locked into place. A wrench head integral with a lever handle rotatably supports a socket for engaging a nut to be driven. The socket is connected to a shank which is integral with a brace, a first portion of which extends perpendicularly outwardly from the shank, and a second portion of which is pivotably mounted with respect to the outer end of the first portion so that the second portion can be turned up to form a crank thus to rapidly spin the socket and consequently the nut to quickly run the bolt up or run down on a bolt. When the nut is to be tightened or broken loose, the outer portion of the brace is folded outwardly, and the entire brace is situated in parallel relationship and in contact with the handle and both are turned to exert the necessary tightening or loosening torque on the nut. This structure presupposes easy access to the nut and to the bolt for the full 360.degree. circle around the longitudinal axis of the nut and bolt and wrench as well as access for a considerable distance outwardly from the bolt in line with its axis.
In U.S. Pat. No. 2,712,765 to Knight, granted in July of 1955, a wrench shank is integral with a shaft which forms a crank handle, and the opposite end of this shaft is rotatably mounted in a pistol grip. For fast operation, the pistol grip and outer end of the shaft are moved in a circular motion about the longitudinal axis of the shank. This provides a high-speed low-torque arrangement. A jaw clutch operable from inside of the pistol grip freezes the outer end of the crank arm against rotation with respect to the pistol grip, and this provides the so-called high-torque low-speed relationship. This structure will not, of course, allow anything like the torque developed by a conventional socket wrench to be applied. A modification discloses a crank arm arrangement for high speed operation, but both forms of the Knight structure require a substantial clearance in a 360.degree. circle around the longitudinal axis of the shank, as well as very substantial clearance outwardly from the bolt along its longitudinal axis.
In contrast to the above, U.S. Pat. No. 2,680,983 to J. T. Miller, granted in June of 1954, discloses a wrench which can be operated in one configuration to apply torque directly to a shank and associated socket head from a handle or can be operated in another configuration to actually slow down the speed of rotation of the shank and associated socket head through gearing in order to increase the torque applied by the handle.
In a preliminary search on this invention, in addition to the patents set out above, the following patents were located. They are not believed to be particularly pertinent to the invention:
U.S. Pat. No. 1,000,878 to Allen in August of 1911; PA1 U.S. Pat. No. 2,420,132 to Gryniuck in May of 1947; PA1 U.S. Pat. No. 2,669,147 to Koenig in February of 1954; PA1 U.S. Pat. No. 2,834,239 to Mancini in May of 1958.
What was needed before the present invention was a ratchet wrench which could be used directly to exert a tightening or loosening force through a shank and a socket head to tighten or loosen a nut on a bolt, this wrench being operable to rapidly move the bolt onto or off of the nut where there is but limited access to the bolt in the full circle around the bolt and where there is no access to the nut and bolt at any considerable distance away from the bolt in the direction of the longitudinal axis of the bolt.
Another example of a wrench having an adapter to spin a nut on or off of a bolt is shown at page 64 of the Sears & Roebuck 1980-81 Fall-Winter Catalog of Power and Hand Tools. In this ad, a conventional ratchet wrench is equipped with a knurled dial extending outwardly between the wrench head and the shank integral with the shank to permit the shank to be rotated manually. To use this feature, the operator must be able to reach the wrench body with his hand.
Applicant and those in privity with him are aware of no prior art which is closer to this invention than that set out above; and they are aware of no prior art which anticipates the claims made herein.